1. Field of the Invention
The present invention relates to a mobile terminal and, in particular, to an enhanced data transport system and a method for a mobile terminal that may provide for an improved transmission rate with fewer errors.
2. Discussion of the Background
In a wireless communication system, information is transmitted via a wireless interface. Such a wireless interface is defined by a wireless protocol and thus, subscriber terminals communicate data with each other based on the wireless protocol. The wireless protocol is developed considering various factors, such as network characteristics including network facilities, terminals, communication environment, and traffic characteristics. Since the 1990's, with the exponential growth of Internet population and usage, Internet traffic has increased dramatically. The majority of internet traffic is Transmission Control Protocol (TCP) traffic carrying data generated by various application programs, such as the World Wide Web (WWW), Teletype Network (TELNET), File Transfer Protocol (FTP), and the like.
In an Internet protocol suite, TCP operates above Internet Protocol (IP) and guarantees reliable and in-order data delivery. TCP uses a sliding window mechanism to control transmission of packets. With the sliding window mechanism, a sender can send a series of packets without acknowledgement. A sender's congestion window and a receiver's advertise window determine the size of the sliding window and a receiver's current buffer size determines the size of its advertise window. The congestion window performs its congestion control.
In a wireless communication system, TCP window size is fixed in accordance with the characteristics of the network. That is, most conventional wireless communication systems use a preset window size for data transmission. In such a case, changes in network characteristics may decrease efficiency. The conventional mobile communication system may be an IS-95A, an IS-95B, a Code Division Multiple Access (CDMA) 1x, a CDMA 1x Evolution Data Optimized (CDMA 1x EVDO), a Wideband CDMA (WCDMA), a Global System for Mobile communication (GSM), or a General Packet Radio Service (GPRS) system. Such mobile communication systems use different packet sizes.
In the current mobile communication systems, a mobile terminal requests transmission and reception of data packets in accordance with preset data transmission environments. Accordingly, data transmission through preset fixed size packets without considering the network characteristics pushes conventional mobile communication systems into pitfalls, such as data loss when high speed burst data passes a low speed network, and inefficient network use when low speed data passes a high speed network.